Yanbu National Petrochemicals and Advanced Petrochemicals 2330.SE fell 2 percent and 1.8 percent respectively.
Travel operator Seera Group fell 5.2 percent after posting a 40 percent drop in its first-quarter net profit, citing competitive pricing and higher costs.
"The interest rate is unlikely to rise, business volumes are likely to be low as we enter Ramadan period, and now weaker crude prices present an ideal gain booking opportunity," analyst Chiro Ghosh at SICO said in Bahrain.
The deep sell-off in the financial sector was profit-taking by investors who had made reasonable gains, Ghosh added.
Last week, Saudi local investors were net sellers of stocks, representing 85.8 percent of total selling activity, while foreign investors were net buyers, according to stock exchange data.
The Egyptian blue-chip index dropped 2.1 percent, with 24 of its 30 stocks declining. El Sewedy Electric plunged 8.1 percent and developer Sixth Of October Development And Investment Co (SODIC) dropped 4.4 percent as the stocks traded ex-dividend.
Non-Arab foreign investors were the net buyers in Monday's session, while Arab investors were the net sellers, according to stock exchange data.
Egyptian Chemical Industries (Kima) was down 6.7 percent. The company reported an 81.7 percent fall in net profit for the nine-month period, while Emaar Misr For Development dropped 6.8 percent after posting a fall in its first-quarter net profit.
"Kima's results are weak, falling short of our estimates by a considerable margin, as the company continued to face hurdles to export its output to Sudan and Turkey," NAEEM Brokerage in a note.
Qatar's blue-chip index slid 1.6 percent, pressured by financial stocks. Qatar Fuel, Qatar First Bank fell 3.9 percent and 3.8 percent, receptively.
The index has risen only 0.2 percent year-to-date, making it one of the worst performing Gulf markets this year.
Out of 10 fund managers polled, most said they would keep their investments in Qatar at the same level, while 40 percent said they would reduce them, according to a Reuters poll last week.
The Abu Dhabi index slipped 1.5 percent, with Finance House and National Bank of Umm Al Qaiwain falling 10 percent and 9.9 percent, respectively. The latter reported a fall in its total income for the first-quarter.
Property developer RAK Properties shed 1.8 percent after it reported an 84 percent slump in first-quarter net profit.
In Dubai, the index traded 0.7 percent, with Dubai Investments sliding 1.5 percent after a 44 percent drop in its first-quarter net profit.
Islamic insurers Dar Al Takaful and Islamic Arab Insurance fell 7.7 percent and 4.2 percent respectively.
(Reporting by Karina Dsouza and Abinaya Vijayaraghavan in Bengaluru Editing by Mark Heinrich) ((Karina.Dsouza@thomsonreuters.com; within U.S. +1 646 223 8780, outside U.S. +91 80 6749 6373; Reuters Messaging: Reuters Messaging: email@example.com))